installing new crank

[QuentinCR250]

I'm thinking of getting a Hotrod crank for my 2001 CR250 which im currently stripping to split the cases. What I want to know is if I buy a new Hotrod crank is there anything I have to do to the crank before I fit it? are they balanced and trued and ready to put straight into the engine? Is there much skill in getting the crank into the cases or just patience and the help of a freezer heating device to expand/contract the appropiate items? I was told I would need help from someone when it came to truing the crank and to ensure truness? surley this would only be the case if the old crank was being rebuilt? thanks

 

[skiboyracing]

The hotrod crank is ready to drop in and go.. It's trued to I think .001. Once you get the bearings and tranny back in the right hand cover, get an aluminum slug that will fit into the inside diameter of the crank bearing. Heat it up with a torch, don't go to crazy or you could turn the bearing blue and ruin it, but just heat it up. Remove the slug and drop the crank right into place. Nothing to it. Then install your gasket, heat the other side up the same way and drop it onto the crank, take a piece of wood and tape it down onto the dowls quickly before the inner bearing cools and your together. No press, no nothing, just a piece of aluminum round stock turned down to the correct diameter.

 

[QuentinCR250]

Cheers for that, then maybe tap the ends of the crank with a plastic hammer to make sure its seated ok?

 

[darringer]

I use a slightly different approach than the excellent post above from skiboyracing. I put the crank in the freezer for a few hours first. Then heat the bearing boss on the clutch-side case and drop the room temperature bearing in. I then repeat the process on the ignition-side case. Take the crank from the freezer and drop in the clutch-side, then put the ignition-side case on the crank and tap the cases together. They always go right together. Then LIGHTLY tap both ends of the crank to make sure it's centered. I've done numerous lower ends this way with zero problems.

 

[CRPilot]

Check Eric Gorr's Site in the Tech Section. He has an excellent writeup on how to do it.